Apparatus for emulsifying liquids and for other purposes



June so, 1931. H. L. SYMONS 1,812,727

APPARATUS FOR EMULSIFYING LIQUIDS AND FOR OTHER PURPOSES Original Filed June 25, 1923 5 Sheets-Shee 1 INVENTOR ATTORNEY H. L. SYMONS June30, 1931.

APPARATUS FOR EMULSIFYING LIQUIDS AND FOR OTHER PURPOSES Original Filed J1me 1925 5 Sheets-Sheet z INVENTOR- v fir'ryl- 67270216.

- ATTORNEY H. L. SYMONS June 30, 1931.

APPARATUS FOR EMULSIFYING LIQUIDS ANDFOR OTHER PURPOSES 5 Sheets-Sheet 5 Original Filed June 25, 1923 .5 I VI'IMVI'IIIIIIIIIIIII/l' INVENTOR //0/7 .5. Q'ymons BY ATTORNEY Patented June 30, 1931 UNITED STATES HARRY L. SYMONS, OF WIMIBLEDON, LONDON, ENGLAND, ASSLGNOB TO ROADS COL- PATENT OFFICE LOIDAL, LIMITED, OF LONDON, ENGLAND APPARATUS FOR EMULSIFYING LIQUIDS AND FOR OTHER PURPOSES Original application filed June 25, 1923, Serial No. 647,421. Divided and this application filed February 29, 1924. Serial No. 695,886.

My invention relates to improvements in apparatus for emulsifying liquids and for other purposes, and the same has for its object to provide a simple, eiiicient and reliable apparatus which may be employed to eco nomically handle quantities of liquids, and which is particularly adapted for use in the production of emulsion or colloidal substances, especially of emulsion of mineral oils in water for use on roads and the like for laying dust.

Further, said invention has for its object to provide an apparatus for emulsifying oils in water by the mechanical disintegration thereof. Y

Further, said invention has for its object to provide an apparatus in which liquids can be combined in predetermined proportions.

Further, said invention has for its object to provide an apparatus in which liquids can be continuously combined in predetermined proportions and which can be regulated to insure said predetermined proportionment of said liquids.

Further, said invention has for its object to provide an apparatus in which immiscible and more or less viscous liquids can be proportioned and combined.

Further, said invention has; for its object to provide an apparatus in which liquids can be automatically proportioned and combined and which can be manually regulated to in sure said predetermined proportionment of said liquids.

Further, said invention has for its object Further, said invention has for its object to provide an apparatus for treating or emulsifying liquids, in which the liquids are continuously supplied, proportioned and com bined therein for treatment.

Further, said invention has for its object to provide an apparatus in which liquids are mechanically treated or emulsified and in which the liquids are continuously proportioned and combined and steadily and efficiently supplied to the treating or emulsify ing means thereof.

Further, said invention has for its object to provide an apparatus, including a mill for treating or emulsifying liquids, in Which a head of supply liquid is maintained to cause a steady flow thereof to the mill and in which means is provided to prevent air looking within the mill.

Further, said invention has for its object to provide an apparatus, including a mill for treat ng or emulsifying liquids, in which the liquids are continuously proportioned and supplied to a receptacle wherein a head of liquid is maintained to insure a steady flow-thereof to the mill and wherein the liquid constituents of said head are maintained separated until entering the mill.

Further, said invention has for its object to provide an apparatus, including a. mill wherein liquids can be treated or emulsified, in which immiscible and more or less viscous liquids are automatically and continuously proportioned and combined and run into said mill to be treated or emulsified.

Further, said invention has for its object to provide an apparatus, including enclosed relatively rotating members, in which immiscible and more or less viscous liquids are continuously and automatically combined in predetermined proportions and steadily and efficiently run between said members to be acted upon thereby, and in which regulating means is rovided to insure the combina tion of said liquids in said proportions.

Further, said invention has for its object to provide an apparatus which is adapted for emulsifying oils in water and an emulsifying agent. and in which the several phases are continuously and automatically combined in predetermined proportions in a receptacle and in which the combined liquids are forced under a head thereof in said receptacle into a mill comprising rapidly rotating members where the same are thoroughly emulsified.

Further, said invention has for its object to provide an apparatus which is adapted for emulsifying oils in water and an emulsifying agent, and in which the several phases are continuously and automatically combined in proportions determined by manual regulations in a receptacle maintaining a head of liquid therein with the constituent phases of said head separated, and in which the combined liquids are forced under the pressure of said head between enclosed rotating members, with the air pressure within said enclosure maintained substantially at that above said head.

Other objects will in part be obvious and in part be pointed out hereinafter.

To the attainment ofth'e aforesaid objects and ends my invention consists in the novel features of construction, and in the combination, connection and arrangement of parts hereinafter more fully described and then pointed out in the claims.

In the drawings forming part of this specification- Figure 1 is an elevation, somewhat diagrammatical, showing one form of apparatus constructed according to and embodying my said invention;

Fig. 2 is an enlarged elevation of a portion thereof, with parts in section and with parts broken away, and illustrating a proportioning hopper or member and emulsifying mill;

Fig. 3 is a plan view of the proportioning hopper; and

Fig. 4 is a. sectional elevation thereof on the line 44 of Fig. 3, looking in the direction of the arrow.

Referrin to Fig. 1, an apparatus or in stallation such as is actually in use at the moment) for performing the process of the Eli-$361113 invention will first be described.-

e approximate grade level or floor of the plant is indicated by the line 10. At the left is illustrated a tank 11, which is used for the storage of the raw oil. In actual practice, for the installation now in use, this tank 11 has a capacit of 4,000 gallons. Tank 11 may be located either on grade level, as shown, or elevated above the level of the heating tanks 12 and 13 to be described. Where the latter arrangement is employed, the oil may then flow by gravity from the tank 11, as required, into the elevated oil heating tanks 12 and 13. However, the arrangement shown is better for gravity flow from the distributting lorries when the distributors supplying the oil in bulk have not the necessary pumps attached to their distributing tank lorries for pumping the oil into an elevated tank.

With the tank arranged as shown, the oil is pumped into the elevated heatin tanks 12 and 13 by means of a pump 14. if tank 11 be elevated, arrangements can be made to pump the oil from the tank delivery'wagon by using the pump 14 and necessary lengths of flexible tubing. For pumping the raw oil from tank 11 into tanks 12 and 13, a pipe 15, extends into tank 11, with its lower end 16 near the bottom thereof and in communication at its upper end with pump 14. The oil is forced by pump 14 through a delivery pipe 17 and the branches 18 and 19 thereof into the elevated oil heating tanks 12 and 13. The pipe 15 is controlled by a valve 20; the pipe 17 is controlled by a valve 21; and the branches 18 and 19 are controlled by valves 22 and 23.

The pump 14 is preferably steam-operated, although other types of pumps may be employed, the necessary steam for the same being generated by means of the vertical boilers 24, which are connected to the pump 14 by means of a pipe 25.

A valve-controlled drainage pipe 26 is shown communicating with the pipe 15.

By the above-described arrangement, the oil in the tank 11 may be elevated as desired to fill the tanks 12 and 13 upon the starting of the pump 14, which is controlled by the valves 20 and 21.

Alternating with the tanks 12 and 13 are elevated heating tanks 27 and 28 for the water and emulsifying agent. A water pipe 29, for supplying fresh water from a source of supply to the tanks 27 and 28, extends above the same and terminates in branches 30 and 31, provided with valves 30a and 31a, for regulating the supply of fresh Water thereto. In the bottoms of the tanks 12, 13, 27 and 28 are steam coils 32 for heating the contents thereof. A steam main 33 in communication with the boilers 24 is connected to the coils 32 through branches 34, each branch 34 being controlled by a suitable valve 35 for shutting off the steam to the coil 32.

The tanks 12 and 27 constitute one set, and the tanks 13 and 28 another, and the contents thereof are alternately run into the emulsif ing mill. By suitable adjustment of t e valves, one set of tanks can be filled and heated while the contents of the other set are being emulsified.

The heating tanks 12, 13, 27 and 28, in the installation actually in use, have a capacity of 800 gallons each, and are fitted with 65 lineal feet of 2-inch steam coil. are located well above the level of the emulsifying mill, the tanks 12 and 13 receiving the raw oils from tank 11 and the binding material, such as bitumen, etc., as hereinafter described, and the tanks 27 and 28 receiving water and a dispersator, stabilizer or emulsifying agent. The steam, after circulating through the heating coils 32, passes through These tanks ',8, steam trap back to a condenser steam main. Such contsruction, however, being Well linowrr and formmg no part of the present inventlon, has not been illustrated.

All of the heating installation should be properly and effectively covered with asbes tos cement or similar preparation, and the heating tanks carefully boxed in with light boarding, providing 2-inch space, which is packed with saw-dust and fine dry cinders. The boiler service is thereby made more officient and economical and the process can be more rapidly performed.

Mounted above the floor 10, below the heating tanks, at such an elevation that the .employees or workmen may conveniently ob serve the same and make adjustments, is a proportioning hopper or receptacle 36. This hopper 36 is provided for the purpose of receiving the heated contents from either set of tanks 12 and 27 or 13 and 28, and proportioning the same for entry into the emulsifying mill. The hopper 36 at its lower end communicates, through a pipe 37, with an emulsifying mill 38, mounted upon a concrete base 39, the supply of material or liquid to the mill being controlled by a valve or cut- 'the hopper 36.

off 40 in the pipe 37. A faucet 40a is also connected to pipe 37 to permit a portion of the liquid to be taken therefrom for testing purposes. The contents of tanks 12 and 13 are delivered into hopper 36 through branch pipes 41 and 42, having the upper ends 43 and 44 of the same located within the tanks 12 and 13 near the bottom thereof and connected at the opposite ends of the same by a common pipe 45, with the lower end of the same located above hopper 36. The branch pipes 41 and 42 are controlled by the valves 46 and 47 therein, and the common pipe 45 has a valve 48 located therein conveniently above The contents of tanks 27 and 28 are delivered into hopper 36 through branch pipes 49 and 50, having the upper ends 51 ad 52 of the same located within the tanks 27 and 28 near the bottom thereof and connected at the opposite ends thereof by a common pipe 53, with the lower end thereof located above the hopper 36. The branch pipes 49 and 50 are controlled by valves 54 and 55, and the common pipe 53 is controlled by a valve 56 conveniently located above the hopper 36.

The hopper 36 (Figs. 2 to 4) comprises a.

cylindrical upper portion and a conical lower portion, communicating with the mill 38 through pipe 37. A proportioning member 57, comprising a tray-like receptacle, is mounted withm the hopper 36 and supported therein by means of hooks 58 thereon extending over the upper edge thereof. The tray 57 is circular .at the 8 rear to permit the same to fit the corresponding surface of hopper 36, and has a fiat vertical wall 59 at the front providing a space between the same to e easily removed from t 1e hopper,

and is spaced upwardlyabove the level of the lower end of the cylindrical portion of the hopper 36. The receptacle 57 is divided by means of a vertical partition 61 into two separate compartments 62 and 63, one located below pipe 45 and the other below pipe 53, to receive the respective liquids conveyed thereby, and so proportioned in cross-section as to permit the liquids from the tanks to flow thereinto in the required proportions for emulsifica-tion, as hereinafter described. As illustrated, the compartments 62 and 63 are of equal volumes, permitting the combination of the liquids in equal proportions. The wall 59 has two V-shaped openings 64 and 65 therein, communicating with compartments 62 and 63, respectively. The openings '64 and 65 are proportioned to permit the liquids to flow therethrough in the required proportionsand, as illustrated, are of equal sizes. Each opening 64 and 65 is closed by a slide 66 guided in the guideways 67 and having a handle 68 at the upper end of the same to lift the same out of the guideways 67 and to replace'fthe same. If so desired, the openings 64 and 65 may be graduated, as shown, to enable the easy observation of the levels of the liquids as the same flow through the openings into the hopper. The conical portion of hopper 36 is divided by means of a vertical partition 69' into separate portions or passages to maintain the liquids flowing through theopenings 64 and 65 separated after the same enter the hopper 36. Partition 69 is spaced below the tray 57 in substantially the same plane with partition 61 thereof, and with its upper edge 70 flush with the upper end of the conical portion of hopper 36, as shown. The lower edge 71 of the partition 69 is spaced upwardly from the inlet to the pipe 37 the passages upon opposite sides thereof communicating with each other at this point, permitting the liquids to combine below edge 71 as the same enter the pipe 37. In practice, the flow of liquids into the hopper is adjusted to maintain the head there of slightly below the upper edge 70 of the partition 69. Hence, even after entering the hopper, the same are maintained separate until entering pipe 37.

A fine mesh gauze or screen 72 islocated above the mouth of the pipe 37, while a similar screen 73 is mounted upon the upper edge of the partition 69 below the member 57 to prevent the passage of foreign or extraneous matter into the mill with the liquid. A valvecontrolled pipe 29a (Fig. 1) connected to the water supply pipe 29 extends above hopper 36 to permit the same to be flushed out.

The ends 16, 43, 44, 51 and 52 of the several same purpose, thereby preventing pump and mill troubles through clogging, etc.

The mill 38 (Fig. 2) comprises a lower casting 74, secured to the concrete base 39 by means of bolts 75, and an upper casting 76, secured to casting 7 4 by bolts 77 ,.and forming therewith an interior chamber or enclosure 78. The mill may be preliminarily heated or continuously heated while operating by admitting steam thereto through the pipe or inlet 79 and removing the same through the outlet 80, or other means may be employed for heating the same. The pipe 37 enters centrally through the bottom of the casting 74 into a dish-shaped space 81 therein. The upper inner surfaces of the walls 82, defining said space 81, extend upwardly and out wardly and constitute a stationary annular frusto conical member concentric with and cooperating with a rotatable frusto conical disc-like member 83 therein, providing a small annular clearance 83a therebetween, diverging upwardly and outwardly, and communicating with the chamber 78, in the lower portion of which said members ars located. The member 83 is secured to a shaft 84, which extends upwardly through a lower bearing in the casting 76 and has an upper bearing in a spider or member 85 mounted on casting 76. The shaft 84 may be adjusted vertically with the upper bearing of the same by means of a micrometer head comprising relative rotatable elements 86 and 87 (not illustrated in detail), thereby adjusting the size of the clearance83a as the frusto conical members move axially relatively to each other. The member 83 is rotated by means of a pulley 88 on shaft 84 driven by a motor 89 (Fig. 1) through a belt 90. The material or liquids, after passing through the clearance 83a into chamber 78, escape therefrom through an outlet 91.

Means is also provided for maintaining the pressure of the air within the enclosure 18 at substantially that of the surrounding atmosphere above the hopper during the operation of the mill. is means comprises a verti- Cally extending pipeor tubular member 92 communicating with the interior 78 of the mill at the upper portion thereof through an air port cover 93, preventing air-locking, bumping and insuring the easy operation thereof. The covers 93 permit access to the interior of the mill to gauge the adjustment 'of the clearance 83a and to permit the same to be washed out and heated therethrough. The outer end 94 of the pipe 92 has an over flow opening, to which a hose may be connected for receiving any abnormal overflow ejected from the mill consequent upon airlock or overload.

The hopper 36 is located a slightly higher elevation than that of the relatively rotatable members 82, 83, so that when the same artition 69, there will be provi a head of liquid above the level of said members tending to force the same through clearance 83a and preventing the admission of air therethrough. This head of liquid, to gether with the provision of pipe 92, maintains a steady feed or flow of liquid into the mill and prevents air-locking and bumping, insuring the easy operation thereof.

The members 82 and 83 are very accurately made to fine limits, and the adjacent surfaces thereof, constituting the walls of clearance 83a, are substantially smooth. While other types of mills may be employed (for instance, the Plauson comprising relatively rotating members having a small clearance between the same), yet the mill illustrated forms a better product, and the same may be accurately adjusted to secure the required clearance for optimum emulsification, as hereinafter described. The member 83 rotates at a high speed, and it has been found, as hereinafter described, that the s eed at which the same rotates is important in order to obtain an optimum product.

The material acted upon by the mill 38 is conducted through the outlet or a pipe 91 into a tank 95 (Fig. 1), located at a level below the mill, and permitting the liquid emulsified by the mill to flow thereinto by gravity. The pipe 91 is controlled by a valve 96, and a valve-controlled branch 97 therefrom is provided for the purpose of draining the pipe 91 and also to permit the drawing off of the material for the purpose of testing the same. The tank 95 should be of a minimum size, double the cubic contents of either pair of heating tanks. The purpose of tank 95 is for the testing of the emulsion before its final reception in the market storage tank. Should the emulsion prove unsuitable, it may be bi-passed into any convenient tank and the raw materials reclaimed or retreated. After the testing of the same, if the material is found satisfactory, it is pumped from the tank 95 through a pipe 98, with the lower end 99 of the same adjacent to the bottom of tank 95, and protected by a screen or sieve, into the market storage tank 100. For this purpose, the pipe 99 is connected to a steam or other pump 101, from which the material is forced into tank 100 through pipe 102, having a valve 103 therein. The pump 10], which is steam-operated and similar to that already described, is connected to the steam supply through the pipe 104: controlled by valve 105. From the tank 100, the finished material is racked off, through a valve-controlled pipe 106, into a barrel 107, ready for shipment.

The tanks described are all preferably tilted towards the outlet corner or end, a

matter of two or three inches, for the purpose of facilitating the cleaning of the same and securing the maximum quantity of contained oil. a

The manner of employing or using the 3P.

' men, supplied in barrels, is unstaved, broken up by hand, weighed, checked, lifted by a pulley to the heating platform, and lowered into the tank 12 in its original form. The bitumen with the oil makes a total of 600 gallons in the tank, which, allowing for the displacement. made by the steam coils 32 therein, provides a convenient quantity with which to work. If so desired, the bitumen may be heated and liquefied separately before it is placed in the tank with the oil, mixing the same with the oil while in-a liquid condition. From pipe 29, into the tank 27 (or 28), is now run 599 gallons of fresh water, the valves 31a and 54 being closed and valve 30a open. To this, 12 gallons'(or approximately 120 lbs.) of sodium oleate (the emulsifying agent) is added, the

water constituting the continuous phase.

Heat should now be applied by admission of steamto the tanks 12 and 27 containing the liquids. This is done by turning valves 35, and the temperature of the oil and bitumen in the tank containing the same should be brought to and maintained at approximately 100 (1, and the temperature of the tank containing the sodium oleate and water should be brought to and maintained at a tempera- I ture of approximately 98 C. The values of temperatures given enable the optimum solution of the bituminous content in the oil without causing the flashingthereof and the optimum solution of the emulsifying agent in-the water. The temperatures of the two liquids being substantially equal, permit the same to safely mix when combined in hopper 36. The heating of the tanks should be continued for about one hour, or until the substances are thoroughly liquid and homogeneous. The bitumen upon heating becomes homogeneous with and dissolved or dispersed through the green tar oil, and the sodium oleate becomes homogeneous with and dissolved in or dispersed through the water. Mechanical stirring may be applied to facilitate the mixing operations, if so desired;

The mill, having been thoroughly cleaned, warmed with live steam to about the temperature of the liquids, run about five minutes to counteract expansion, and the clearance 83a between the members 82 and 83 having been set at the required value, as hereinafter described, the motor is started. The valves 46 and 54 are now opened and the valve 40 closed. The valves 48 and 56 are then gradually opened above the proportioning hopper 36, the same having been previously marked so that both compartments 62 and 63 of the tray 5? of the hopper fill at approximately, the same rate in equal volumes and at the approximate maximum rate of flow satisfactory to the production of stable emulsion subject to the mills capacity. The sliding panels 66 are then raised and the heated raw materials allowed to fill the hopper 36 upon 38 at a temperature of about to 85 (3.,

to which the same have meanwhile fallen by radiation, through the clearance 83a, in the desired proportions (for one product, light in bitumen content) of 49% water, 1% dispersator or emulsifying agent, 10% green tar oil and 10% bitumen. The attendant can note if these proportions are being maintained by observing the levels of the liquids as the same issue through openings 64 and 65, and may insert panels 66 from time to time to note if the liquids are entering the compartments 62, 63 at the same rate. From the mill, where the oil and bitumen are thoroughly emulsified in the water and emulsifying agent, the finished product flows by gravity into the catch tank 95.

The tank 95 is for the purpose of catching one whole runfrom any two heating tanks 12 and 27 or 13 and 28, so that if there are any faults in the materials or manufacture, the particular lot may be bypassed into other tanks (not illustrated, but which may be easily arranged) and not allowed to injure the supply of material already in the market storage tank 100 or hold up further production. This product in thetank 95 is now analyzed by the chemist, and if found uusatisfactory is retreated by repassing the same through the mill or the raw materials reclaimed. The material treated by the mill redistributing any heavy material which may not have been properly emulsified but which is in sufiiciently small quantities as not to materially afi'ect the final product when placed in the barrels 107', into which the material is racked off by ordinary methods and shipped out for consumption.

In marketing the product in barrels and containers, the latter should be carefully steamed, cleaned and inspected before filling and should preferably be treated with a mixture of water and caustic soda to thoroughly cleanse the same. I find metal containers best.

After the tanks 12 and 27 are filled and heated and the contents of the same are being run through the mill, the tanks 13 and 28 are then filled and heated, the contents thereof being ready for treatment in the mill after the contents of the first set of tanks are emulsified. Thereupon the first set of tanks is filled and heated, the process being contin uous.

With an equipment of the size above mentioned, which is now in actual use, the plant would have a capacity of 6,000 gallons per 8-hour day. This means 1% hours for each run of 1,200 gallons to fill, heat and run through the mill and allowing for stoppages and unforseen contingencies. The above production is possible by using two sets of heating tanks, tanks 12 and 27 and tanks 13 and 28, as shown, the mill 38 being designed, for the production stated, to have a ca acity of 1,000 gallons per hour.

he mill actually employed to obtain the above-mentioned production had a member 83 with a top diameter of approximately 15 inches and a bottom diameter of approximately 11 inches, the member 83 being about 2 inches thick and the clearance 83a between the members 82 and 83 being about 3 inches long. The mill 38, however, may be of any suitable size according to the production required.

One run of the liquids through the mill .is usually suflic'ient in the process above described, especially when passed therethrough in a heated condition. After use, the mill 38 should be thoroughly cleansed by running water and dispersator through the same and finally water alone until thoroughly clean.

The level or head of the liquid in the hopper 36 is maintained above the level of the member 83, providing a head of liquid, tending to force the material through the clearance 83a between the members 82 and 83 and providing a liquid seal, preventing the admission of air to the chamber 78 and, in cooperation with the maintenance of atmospheric air pressure within the chamber 7 8 by the pipe 92, permitting the mill to run smoothly at full load.

In adjusting the flow of the liquids into the hopper 36, the delivery pipes 45 and 53 compartment.

from the raw oil and dispersator heating tanks meet just above the tray, one pipe per The valves 48 and 56 are conveniently located above the hopper. These valves should be slowly opened at the same time, the raw materials flowing into the two compartments. The valves may be marked roughly when the liquids in the two compartments are rising at the same rate and are being maintained subtantially at equal levels. When the valve adjustment has been obtained, the traps or slides 66 are then simultaneously opened and the proper quantities allowed to flow into the hopper 36, where the same are maintained separate until entering pipe 87, thus insuring the combination thereof in the required proportions for emulsification. Whether or not the flow is being maintained in equal proportions will be roughly determined by noticing the elevation of the liquids as the same come through the openings 64 and 65. The elevation of one should be substantially that of the other. Some little adjustment will be required before the valves can be marked roughly to show whether the mill is being properly supplied with the liquids and in the required proportions. The'system, however, can soon be adjusted to run continuously and automatically and to combine the liquids while running, permitting the proper proportioning of immiscible liquids which are more or less viscous and do not mix. The slides 66, however, should be dropped from time totime to note the rise of liquids in the compartments and to determine if the same are entering at the same rate and are being maintained at equal levels.

The quality of the final product depends to a certain extent on the temperature at which the mixture is passed through the mill, although when the oil and bitumen are thoroughly mixed, the same may be emulsified when cold. For the composition comprising the ingredients as above specified, the liquids should preferably be at a temperature of approximately to C. when acted upon by the mill and passed therethrough once.

The speed of the mill and the clearance between the members 82 and 83 is also important. F or instance. it has been found, for the product as above described, that a clearance of 10/1000ths of an inch at 4,500 revolutions per minute was not as effective as one of 15/1000ths of an inch at the same speed. Nor did a speed of 3,500 revolutions per minute and a clearance of 5/1000ths of an inch give as good results as a speed of 4,500 revolutions per minute and a clearance of 15/1000ths of an inch. As at present determined, for the above-described product, a speed of roughly 4,500 revolutions per minute with a clearance of 15/1000ths to 20/ 1000ths of an inch is the best. These values will vary, however, with variations in the prod- A. B C D Per cent 30 45 25 Per cent Per' mi The oil is preferably green'tar oil as meeting the requirements for an efficient product. The percentage of emulsifying agent 15 included in the percentages given for water. The percentage of bitumen or other bltum nous or binding substance employed varies with the requirements for the dust preventative material the larger the percentage thereof, the greater will be the binding propertles of the composition or product.

Emulsions of mixtures of mineral oil and bituminous substances containing more than approximately 40% or 45% by volume of b1- tuminous substance in said mixture have not been obtained in a satisfactory state, possibly owing to the high viscosity thereofand the resistance of the same to the disintegrating action of the mill. While emulsions have been obtained containing such excess'of bitumen, the dispersion is poor and emulsification is incomplete.

Anotherconsideration in the manufacture of the product or compositionof the present invention is the amount of water employed. Owing to the cost of transportation, as little water as possible should be employed consistcnt with complete emulsification. In the process herein described, the amount of water need not exceed 50% ofthe total volume of the ingredients employed (although more may be employed) and may be as little as 25% of the total volume of'the ingredients. When the oil and bitumen are mixed with water anddispersator in the proportions of three to one, the cross-sections of the compartments 62 and 63 and of the openings 64 and 65 should be likewise proportioned, so that the liquids, when rising at the same rate and being maintained at equal levels therein, as noted, are entering the tray and hopper in the required proportions of 3 to 1.

When a natural oil containing bitumen therein in the required proportions is avail-- able, it need not be necessary to. artificially mix the mineral oil, such as green tar oil, and the bituminous substance, such as bitumen. For instance, Norfolk residual oil,'containing approximately 30% bitumen by volume, may be employed in the above-described process to make the product or composition.

In lieu of green tar oil,'other oils may be employed in the process and product, having the required capacity to emulsify, to dissolve the binding material, and having dust-layin g properties. Such oils should be, preferably, mineral oils, such as certain shale oils, and contain other crude oils, for example, paraffine oil or the Norfolk oil above mentioned.

The binding material employed can be any 'of the bituminous substances prevalent, such as the one herein employed, or certain substances of an asphaltic natureand having the requiredbinding properties and the capacity to emulsify.

The green tar oil employed is a normal gas works product after the extraction of anthracene, etc. The bitumen employed met the following requirements:

Melting point (ring and ball) 135 F. Penetration Not under 43 Ductility 100 Fixed carbon 17)? Solubility in carbon bisulphide 19.9)?

The green tar oil employed was found to contain soluble gases to the extent of 1.085%, water 1%, and tar acids 5%, these materials being considered impurities therein. The first drop of green tar oil as used distilled over at approximately 200 0., and at 320 C. 60% of the same is distilled.

The emulsifying agent, stabilizer or dispersator maybe any of. those capable of emulsifying the oil and binder and of maintaining the particles thereof in a stable condition, preventing the same from agglomerating or forming a gel. The particular dispersator or emulsifying agent used or the proportions thereof employed will vary with the nature of the oil employed or with the nature of the material to be emulsified. As herein described, however, I prefer to use asoap, such as sodium oleate, although similar substances may be used, such as potassium oleate or gelatine or combinations of such sodium or potassium oleates with gelatine. The emulsifying agent, however, should be such as will cause the emulsification of the oil and bituminous substance in the' commercial oleic acid and caustic soda to.

give a 2% solution of neutral soap. Since the fineness of the subdivision of'the dispersed phase depends in a large measure on the concentration and on the alkalinity or acidity of the dispersator in use, the latter must be very carefully prepared and used in the correct proportions. The sodium oleate given by way of example and comprising the preferred dispersator is formed by the admixture of the theoretical quantities of oleic acid and caustic soda for the normal reaction to take place according to the equation C I-I COOH+NaOH= C H COONa-l-H O The product formed by the above-described process is a colloidal or emulsified preparation of bitumen and a mineral oil for use as a dust preventative for roads, mines and the like. The composition is an ideal one for this purpose, as it prevents not only the dispersion of dust already formed, but also retards the formation of further dust by attrition. The first of these functions is filled by the oil in the water by reason of its saturating power, the effectiveness of the oil depending upon the rate of evaporation thereof. The second function is fulfilled by the adhesive or binding qualities of the preparation which are given to it by the bitumen content. From a chemical point of view, the composition of my invention is, it is believed, a colloidal or emulsified solution in which the internal or dispersed phase is a solution or mixture of a bituminous substance, such as bitumen, in an oil, preferably a mineral oil, the latter acting as or like a solvent, and in which the exteral, continuous or dispersing phase is water containing the necessary emulsifying agent. The finished product is of a light chocolate color, miscible with wa ter in all proportions, from 10 to 20 volumes being addable thereto without detrimental efiect. The color, of course, becomes lighter as more water is added. For a given bitumen content, the color will be a rough indication of the quality, since the finer are the subdivisions of the emulsified oils, the lighter will be the color. On standing, little or no separation takes place in the product or composition. Two types of separations may occur when the materials have not been properly mixed or properly prepared. One, the arising to the top of a light colored layer; the other, the settling to the bottom of a darker layer. The former, although undesirable, can be tolerated, as it is a layer of very finely divided but dilute emulsion. The latter, however, cannot be passed, as it consists of a layer in which the particles are coarser globules or are even grains of bitumen. The latter is very unstable and not as miscible in water.

The chief characteristics of the product or composition of this invention are as follows:

A good sample shows, when in a thin film between the slides and cover glass, upon observation through a high-powered microscope, a densely packed mass of distinct particles or globules of diameters approximating the order of magnitude of a small fraction of a millimeter, i. e., 2 to 3 X 10 mm. or of the order of magnitude required to permit Brownian motion, the particles or the larger portion thereof being in rapid Brownian motion. Dilution with water to equal extents enables the number of particles per given area to be compared between difi'erent samples, the particles here being in rapid Brownian motion also. Those samples which show a coarse grain or in which the particles show a tendency to form aggregates will prove unstable and will separate on standing. The composition of my invention, however, when made in accordance with the above-described process and in the proportions herein specified, comprises a stable, colloidal substance or emulsion, miscible in water in all proportions.

The viscosity of the composition, when comprising by volume green tar oil 40%, bitumen 10%, water49%, and sodium oleate 1%, as above manufactured, is approximately 5.5, as determined by the Ostwald vixcometer, and approximately 11 when the bitumen is increased to 15%. As the viscosity increases above that specified, there will be a tendency for the particles to aggregate and for the bitumen to separate.

The 10% bitumen composition above mentioned will not precipitate when five centimeters thereof are added to 10 centimeters of a .25 normal sodium chloride solution, the same remaining unchanged for five minutes. Higher concentrations of sodium chloride solution, however, precipitate the same.

Dilution with water has no effect on my composition when made in accordance with the process above described. The water em ployed in manufacture, however, should be the minimum required for the complete emulsification of the oil and binding material therein, thereby enabling the cheap trans ortation of the same. When the material,

owever, is to be used at its destination, addi tional quantities of water may be added to any required extent, the composition becoming homogeneous with the water and being misclble therewith in all proportions. This provides a composition which can be placed in any sprinkling cart and applied just like water.

The water employed in the manufacture of the composition of my invention should not be too hard, and an excess of emulsifying a cut should not be employed, as the presence 0 salts or electrolytes beyond a certain concentration tend to precipitate colloidal solutions.

For the above reason, the composition of my invention is modified where it is contemplated to dilute the same with salt water or sea water to sprinkle the same over the road or surface. To permit such use, the presence of gelatine in the composition to the extent of 1% affords protection against the precipitating influences of sea water: ,In the preparation of the emulsion, therefore, for use with sea water, the gelatine is added as a 2% solution either with sodium oleate in the course of manufacture-or preferably it may be added afterwards to the finished product.

The product hereindescribed as manufactured by;,.my.proces$rprovides a composition for roads,.mines,,railways and other surfaces of all kindsfwhich; is far superior to the watering. and ,tar-spraying methods herebefore in use, which are-imperfect and expen-. sive, and have..many disadvantages. My composition is cheaper to. use, .asit need not be applied as. often, and the distribution is more even and economical. Furthermore, it is easily, applied and .is non poisonous and non-slippery. It is applied bymixing therewith from 10 to 20 times its bulk; ofwater and sprinkling ,the. samejon the roads with an ordinary sprinkling. cart. 1 The liquid soaks into the-road, thewater evaporates, and the bitumen and oil remain. When applied, the same prolongs the life of the road, prevents cracking. thereof and the, Wearing away thereof. The samedoes not adhere to vehicles nor cause inconvenience to pedestrians.

My composition is manufactured with varying proportions ,of, binding material.

When a light dust dressing is desired, the

' bitumen content is less. In the case of water bound macadam, gravel roads. etc., in poor repair, a maximum-quantity of bitumen is included, affording greaterbinding property.

The penetration "of my composition is virtually that V of water as also is its specific gravity. It penetrates where water will go, leaving the oils permeated within the surface, coating and binding each particle of the surface with oils and bitumen.

By reason of theetficiency of the same in laying dust, it is invaluable from a health standpoint, the green tar oil also being a disinfectant.

' rials, the same does not become dust upon drying but remains on the road and does not run off polluting streams.

Furthermore, my composition, which is non-inflammable, is especially valuable for in mines to prevent explosions and fires. For this purpose, the passageways in the mines are swept, and my composition is sprayed in a moderate soiution with water on floors walls. coal dust is thoroughly prevented thereby from causing explosions, etc.

.-.The above described rocesses and the products resulting there romv are disclosed and 'claimedin a copending application for Letters, Patent ofthe United States, Serial No. 647,421, filed b \meiJune' 25,1923, the present application. eing a division. thereof. The advantages possessed by the apparatus embodyingmy said invention and herein shown and described will be apparent from the quality of the product above described, resulting therefrom and from the process employed My mvention permits of the ready and continuous proportioning and combination of liquids which are more or less viscous and diflicult to handle and which. are immiscible in each other. This proportionment is regulated by hand until the liquids rise in the compartments 62 and 63 at the same rate or until the. same enter said compartments at such relative rates that the liquids pass out through the V-shaped openings 64 and 65 at the required rates, being maintained in said compartments at the same or different levels according to the proportions in ,which the same are tobe combined.

Another feature of my said invention is the provision of means for maintaining a head of liquid above the level of the relatively rotatable members 82, 83 while keeping the liquids therein in the proper proportions for entry into the mill 38. The tapering hopper 36 and partition 69 keep the liquids separated until the same run into the mill, thus insurin the maintenance of the said proportions, an preventing the liquids from forming layers one above the other in accordance with their densities.

Owing to the speed at which the member 83 rotates and to the diverging character of the clearance 83a the liquids are rapidly drawn by the centrifugal action thereof through the mill and thoroughly emulsified, forming a frothy mixture and suds of increased volume, thus tending to overload the mill and to cause the same to become air locked. The provision of the tubular member 92 not only prevents air locking witl in the chamber 78 but also serves to receive eject the over-- flow of material from the chamber 78 should the mill become excessi eiy overloaded. The ejection of material through pipe 92 also indicates to the attendant that the mill is being overloaded, whereupon the valve 46 can be adjusted as well as the valves 48 and 56 to secure a steady and optimum flow of liquids to the mill. Upon overloading, the liquids also .tend to back up in hopper 36, and, since it is preferable not to maintain the head at a level above the screen 70, the valve &0 or the valves 48 and 56, or all, can thereupon be regulated accordingly. The valve 46 when closed also permits the initial filling of the receptacle 36 to form the head of liquid therein. Thus it-will be seen that the present invention "is characterized by the adjustments for securing and maintaming an optimum condition of operation;

My said invention therefore not only insures accurate and convenient proportioning of the constituent phases of my emulsion and their combination, but also insures optimum and efficient operation of the mill thereon to produce the product or composition having the many advantages above described.

Having thus described my said invention,

what I claim'and desire to secure by Letters Patent is 1. An apparatus of the character described comprisinga mill for subjecting a liquid to the action thereof, means for continuously maintaining a contant head of liquid above said mill, means for continuously supplying liquid to said head, and means for preventing air locking in said mill.

2. An apparatus of the character described comprising a mill for subjecting a liquid to the action thereof, means for continuously maintaining a constant head of liquid above said mill, means for continuously supplying liquid to said head, means for preventing air locking in said mill, and means for regulating the fiow of liquid.

3. An apparatus of the character described comprising relatively rotatable members having a clearance between the same, a caslng enclosing said members and forming a chamber at one side thereof, an inlet at the opposite side thereof for supplying liquid thereto, an outlet from said chamber, means for maintaining said inlet liquid sealed and for steadily suppl ing liquid therethrough to said members, an a tubular member mounted on said casing and constituting means of communication between said chamber and the exterior of said casing said tubular member extending vertically above the normal level of the liquid in said chamber and adapted to receive liquid upon overloading of said apparatus therewith.

4. An apparatus of the character described comprising relatively rotatable members having a clearance between the same, a casing enclosing said members, an inlet thereto, an outlet therefrom, a receptacle communicating with said inlet, extending above the level of said members and constituting meanslfor maintaining a head of liquid above the level ing therein above the level of said head of liquid and constituting means of communication between the interior of said casing and the exterior thereof.

5. An apparatus of the character described comprising relatively rotatable members,

having a clearance between the same, a casing enclosing said members, means for continuously maintaining a fixed head of supply liquid at a level above said members for steadily feeding the same thereto, an,outlet in said casing, and means on said casing to prevent air locking within the same.

6. An apparatus of the character described comprising relatively rotatable members having a clearancebetween the same, a casing enclosing said members, a receptacle having a downwardly tapered lower portion, a partition vertically and transversely arranged therein, a conduit connecting said tapered portionwith said casing below said members, a valve controlling said conduit, an outlet in said casing upon the opposite side of said members, said receptacle constituting means for maintaining a head of liquid therein above the level of said members to insure a steady flow thereto, a tra like proportioning member mounted on sai receptacle at the upper portion thereof, said last-named member having compartments, said compartments having openings therein communicating with said receptacle at opposite sides of said partition, means for controlling said openings, pipes for supplying liquids to said compartments, valves for regulating the flow therefrom, as determined by the rise of 1iquids in said compartments, when said 0 enings are closed, and a vertically exten ing pipe mounted on the upper portion of said casing and communicatin with the interior thereof to prevent air loc ing therein.

7. An apparatus of the character described comprising a mill having a discharge orifice at the outlet side thereof, a receptacle for receiving liquids to be combined and communicatmg with said mill, said receptacle constituting means for maintaining a head of liquid therein to provide a steady fiow of liquid to said mill, means for venting the outlet side of the mill to prevent back pressure therein from causing variations in level of the head of liquid in said receptacle, and means for severally supplying liquids to said receptacle.

8. An apparatus of the character described comprising a mill having a discharge orifice at the outlet side thereof, a receptacle for receiving liquids to be combined and communicatmg with said mill, said receptacle constituting means to maintain a head of liquid therein to provide a steadv flow of liquid to said mill, means for severally supplying liquids to said receptacle, means for venting the outlet side of the mill to prevent back pressure therein from. causing variation in level of the head of liquid in said receptacle, and means for automatically proportioning said liquids to be acted upon by said mill and controlling the head level.

9. An apparatus of the character described comprising a mill having a discharge orifice 13 taining a head of liquid therein to insure a steady flow thereof to said mill, means for severally supplying li uids to said receptacle,

means for maintaining said liquids constituting said head separate, and means for venting the outlet side of the mill to prevent air pressure in the mill from affecting said head.

10. An apparatus of' the character described comprising a mill, a downwardly tapering receptacle adapted to receive liquids to be combined, a conduit connecting said receptacle and said mill, said receptacle constituting means for maintaining a head of liquid therein to insure a steady flow thereof to said mill, a partition interposed across the tapered portion of said receptacle, and means for severally supplying liquids thereto at opposite sides of said partition.

11. An apparatus of the character described comprising a mill, a downwardly tapering receptacle adapted to receive liquids to be combined, a conduit connecting said receptacle and said mill, said *receptacle constituting means for maintaining a head of liquid therein to insure a steady flow thereof to said mill, a partition interposed across the tapered portion of said receptacle, for severally supplying liquids thereto at 0}),- posite sides of said partition, and automatic means for proportioning said liquids as the same enter said receptacle at opposite sides of said partition.

12. An apparatus of the character described comprising a mill, a receptacle having a downwardly tapering portion, an outlet at the lower end of said tapering portion communicating with said mill, a vertically arranged partition therein, a traylike proportionin member mounted on the upper portion '0 'said receptacle and having com; partments therein, said compartments having openings communicating with said re: ceptacle at opposite'sides of said partition 'for supplying liquids to said receptacle at opposite sides of said partition to form a divided head of liquid above said mill and means for controlling said openings.

13. An apparatus of the character described comprising a pluralitv of tanks adapted to receive liquids to be emulsified, a receptacle adapted to receive liquids therefrom to be combined, means for severally conveying said liquids to said receptacle, proportioning means to cause said liquids to combine therein in predetermined proportions, an emuslifying mill, and means for conveying said combined liquids thereto.

14. An apparatus of the character described comprising a plurality of sets of tanks adapted to receive liquids to be emulsified,

means for heating the contents of said tanks,

a receptacle adapted to alternately receive the contents of each set of tanks to combine the same, means for severally conveying said liquids to said receptacle, proportioning means to cause said liquids to combine therein in predetermined proportions, an emulsifying mill, and means for conveying said combined liquids to said mill.

15. An apparatus of the character described comprising an emulsifying mill, a.

rece tacle adapted to receive liquids to be com ined and constituting means for maintaining a head of liquid for insuring a steady supply thereof to said mill, means for preventing air locking within said mill, means for severally and continuously supplying liquids to said receptacle, means for continu ously and automatically proportioning said liquids as the same enter said receptacle, and means for manually regulating said automatic means to insure the combination of said li uids in predetermined proportions.

16. n apparatus of the character described comprising an emulsifying mill, a

receptacle adapted to receive liquids to be combined and constituting means for maintaming a head of liquid for insuring a steady supply thereof to said mill, means for maintaining the liquids constituting said head separated, means for severally and continuously supplying liquids to said receptacle, means for continuously and automatically proportioning said liquids as the same enter said receptacle, means for manually regulating said automatic meansto insure. the comblnation of said liquids in predetermined proportions, and means to prevent air locking in said mill.

17. An apparatus of the character described comprising a mill having a discharge orifice at the outlet side thereof, a receptacle for receiving liquids to be combined and communicating with said mill; said receptacle constituting means for maintaining ahead of liquid therein to provide a steady flow of liquid to said mill, means for venting the outlet side of the mill to prevent back pressure therein from causing variation in level of the head of liquid in said receptacle, means for severally supplying liquids to said receptacle, and means for regulating the flow through each of said last named means.

18. An apparatus of the character described comprising a mill having a discharge orifice at the outlet side thereof, a receptacle for receiving liquids to be combined and communicating with said mill; said receptacle constituting means for maintaining a head of liquid therein to provide a steady flow of liquid to the mill, means for venting the outlet side of the mill to prevent back pressure therein from causing variation in level of the head of liquid in said receptacle, a proportioning member associated with said receptacle and having compartments therein communicating with said receptacle, and means for severally conveying liquids to said compartments.

19. An apparatus of the character described comprising a mill having a discharge orifice at the outlet side thereof, a receptacle adapted to receive liquids to be combined and communicatin with said mill; said receplacle constitutlng means for maintaining a head of liquid therein to provide a steady flow of liquid to the mill, means for venting the outlet side of the mill to prevent back pressure therein from causing variation in level of the head of liquid in said receptacle, a proportioning member associated with said receptacle and having compartments therein, means for severally conveying liquids to said compartments, means for regulating the flow of liquids therefrom, said compartments having openings therein to permit flow of liquids therefrom into said receptacle, and means for controlling said openings.

20. An apparatus of the character described comprising a mill having relatively rotatable members providing a constricted clearance therebetween, and having a discharge orifice at the outlet side of the mill, means for severally supplying liquids continuously to said mill, means for regulating the flow of each thereof to supply the same in the requisite proportions, means for maintaining the inlet to said mill liquid sealed and supplying the proportioned liquids thereto at a rate to prevent overloading, and means for venting the outlet side of the mill to prevent back pressure therein from exceeding the pressure efiective in causing flow of liquids to the mill.

Signed at the city of New York, in the county and State of New York, this 2nd day of August, one thousand nine hundred and twenty-three.

HARRY L. SYMONS. 

